Nanoporous Silver Submicrocubes Layer by Layer Encapsulated with Polyelectrolyte Films: Nonenzymatic Catalysis for...

Area of Science:

• Nanomaterials Synthesis and Characterization
• Electrochemical Sensing Technologies
• Surface Chemistry and Coatings

Background:

• Nanoporous silver submicrocubes (Np-Ag) are promising platforms for catalysis.
• Electrochemical sensing requires stable and efficient electrode materials.
• Layer-by-layer (LBL) assembly offers precise control over surface coatings.

Purpose of the Study:

• To synthesize Np-Ag capped with poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate) (PSS) bilayers.
• To investigate the LBL assembly process and characterize the resulting nanomaterials.
• To evaluate the performance of these modified electrodes for electrochemical glucose sensing.

Main Methods:

• Synthesis of nanoporous silver submicrocubes (Np-Ag).
• Layer-by-layer (LBL) assembly of PAH/PSS polyelectrolyte bilayers on Np-Ag.
• Characterization using ζ-potential analysis, high-resolution transmission electron microscopy (HR-TEM), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) with elemental mapping.

Main Results:

• Successfully synthesized Np-Ag particles capped with 1 to 4 PAH/PSS bilayers.
• ζ-potential analysis confirmed successful layer deposition and charge reversal.
• HR-TEM and elemental mapping validated the uniform thickness (approx. 4 nm for 2 bilayers) and high quality of the polyelectrolyte capping.
• The Np-Ag(PAH/PSS)2 electrode exhibited optimal electrocatalytic activity for glucose.
• The Np-Ag(PAH/PSS)2 electrode achieved a detection limit of 20 μM, sensitivity of 472.15 μA mM⁻¹ cm⁻², and selectivity for glucose up to 23.3 mM.

Conclusions:

• The LBL assembly technique provides precise control over polyelectrolyte film thickness on Np-Ag.
• The Np-Ag(PAH/PSS)2 electrode demonstrates excellent performance for electrochemical glucose sensing.
• This approach enhances the stability and performance of particle-type catalysts on electrode surfaces.